A simmering dispute over pay and working conditions at a Phnom Penh garment factory has led to arrests and scuffles between workers and police, and accusations of excessive violence by the officers. The incident occurred during an important fact-finding visit by U.S. State Department officials.

Phnom Penh Police Chief Suon Chheang Ly said seven garment workers were released from custody only hours after they were arrested. The workers, employees of the Wonrex garment factory, were detained after an hour-long clash with riot police Wednesday morning.

The workers intended to march to Cambodia's National Assembly to protest forced overtime and improper pay, over which they have been demonstrating for a week. However, eyewitnesses said tensions boiled over between some 300 workers and 200 policemen, who used electric batons on some of the protesters.

By midday, the situation at the factory was calm and the police had been withdrawn. But the president of the Free Trade Union of Workers, Chea Vichea, and Chheam Channy, an opposition member of parliament who participated in the demonstration, accused the authorities of using excessive force.

Mr. Channy said he received several welts on the lower part of his body from the electric batons. The police chief denied Mr. Channy had been assaulted, saying that had authorities really wanted to beat the member of parliament, he would be dead.

The protest occurred the same day that members of a U.S. government delegation were in Phnom Penh to assess Cambodian garment factory conditions. Robert Hagan, the director of the U.S. State Department's Office of International Labor Affairs, told reporters that a Cambodian arbitration council set up in May should have been used to resolve the kind of dispute that led to the morning's violence.

However, he said the general situation at Cambodian factories appeared to be improving, and there seemed to be a better relationship between workers and management.

Mr. Hagan's eventual report to the U.S. government will help decide the amount of trade quota that Cambodia receives for 2004. Improvements in working conditions and labor rights earn the garment industry increases in the amounts it can export to the United States.

The American market is vital to Cambodia's garment industry. Since passage of the 1999 U.S. / Cambodia Bilateral Textile Agreement, the industry's exports have quadrupled, to $1.3 billion, and the number of workers employed has grown from 80,000 to more than 220,000.